Fluid pressure motor construction



April 2, 1963 E. R- PRICE ETAL 3,083,698

FLUID PRESSURE MOTOR CONSTRUCTION Filed June 30. 1960 2 sheets sheet 1 lanai INVENTOR. EARL. R. PRICE- ROBERT R. HAGER GUNTHER PFEIFEIZ.

DONALD L HOOVER.

April 1963 E. R PRICE ETAL 3,083,698

FLUID PRESSURE MOTOR CONSTRUCTION Filed June 50, 1960 2 Sheets-Sheet 2 INVENTOR. EARL )2. PRICE. DONALD L. Ham E2 ROBERT R. HAGER Gun-r1452 PFE/FEL.

I atented Apr. 2, l63

tar-A 3, 383,698 FLUEB E REFBSURE CONSTRUCTIGN Earl R. Price and Donaid L. Hoover, outh Bend, and Robert E. Huger, Elkharl, End, and Gunther Pieitcr, Buchanan, Mich, assignors to The Bendix Corporation, South Bend, End, a corporation of Delaware Filed lune 3%, Ser. No. 3?;932

11-31] Claims. 121-43) The present invention relates to a new and improved construction for the shells of fluid pressure motors and the like; and more particularly to an inexpensive housing for a fluid pressure servomotor.

An object of the present invention is the provision of a new and improved construction for securing end sections of the shell of a fluid motor and the like together.

Another object of the present invention is the provision of a new and improved stamped sheet metal shell for a fluid pressure motor and the like.

A more specific object of the present invention is the provision of a new and improved fluid pressure motor housing having a new and improved stamped configuration for locking its end sections together.

The invention resides in certain constructions and combinations and arrangements of parts; and further objects and advantages will become apparent to those skilled in the art to which the invention relates from the following description of the preferred embodiment described with reference to the accompanying drawings forming a part of this specification, and in which:

FIGURE 1 is a cross sectional view of a tandem piston vacuum submerged fluid pressure servomotor embodying principles of the present invention;

FIGURE 2 is an end elevational view of the servomotor shown in FIGURE 1; and

FIGURE 3 is an enlarged fragmentary view of the locking means used to fasten the two end sections of the servomotor housing together.

The fluid pressure servomotor shown in flGURE 1 generally comprises a tandem piston vacuum submerged unit whose shell is formed by means of a front cover section it) and a rear section 12 as will later be described in detail. The internal chamber of the shell A is divided into front and rear sections by means of an internal partition member B; and the movable wall structure or power piston C of the motor is formed by -a centrallylocated rigid structure which slidingly sealingly proiects through the partition member B so as to have portions lying forwardly and rearwardly of the partition member B. This movable wall structure C is formed by means of a cast hub 14 that is axially positioned rearwardly of the partition member B and to which is suitably bolted a tubular boss or projection 16 which extends forwardly through the partition member B. A suitable diaphragm plate 18 is bolted between the tubular boss 16 and hub 14, and another diaphragm plate 2% is suitably fixed to the portion of the hub 16 that is positioned forwardly of the partition member B. Diaphragms Z2 and 2d are suitably positioned on the rear surfaces of the diaphragm plates 18 and 29 respectively with their radially inner edges sealed to the movable wall structure C, and their radially outer ends suitably fixed to the shell of the servomotor A. The front diaphragm 24 therefore divides the space forwardly of the partition member B into front and rear power chambers 26 and 28 respectively, and the rear diaphragm 22 divides the space rearwardly of the partition member B into front and rear power chambers 3t: and 32 respectively.

The servomotor shown in the drawing is or" the type which is actuated by means of vacuum-to-atmospheric pressure differential, and has further been designed so that vacuum is communicated to all of the power chambers 26, 28, 3t and 32 in the normal de-energized condition of the servomotor. Control of the servomotor is had by means of the valve structure E which is positioned in and carried by the movable wall C, and in which in turn is actuated by means of the push rod or control rod D. Vacuum is continually communicated to the front power chamber 26 by means of the connection 34, from whence it flows through the central opening 36 of the tubular boss 16 to a lateral opening 38 which communicates both with the front power chamber 39 and a passageway 40 leading to the control valve structure E.

The cast hub 14 which forms the various passages of the control valve structure E is provided with a rearwardly extending tubular projection 42 which extends out through and is suitably sealed with respect to the rear end structure of the servomotor shell A. The hub 14 is provided with an internal partition -44 having an axially extending opening therethr-ough forming the control port 46 of the valve structure E, and which is surrounded with a realwardly facing vacuum valve seat 4-8. An annular valve closure member 5% is positioned rearwardly of the vacuum valve seat 43 for abutment therewith, and the valve closure member '59 is provided with a rearwardly and radially outwardly extending diaphragm portion 52 which is suitably clamped and sealed with respect to the sidewalls of the rearwardly extending tubular portion 42. A mounting plate 54 is spot-welded to the rear face of the shell A surrounding the tubular projection 42 in a manner providing for the passage of air between the shell A and plate 54 to the region surrounding the tubular projection 42. A flexible boot or dirt seal 56 is provided between the plate 54 and push rod D to cause air to flow around the tubular projection and into its internal opening 53 through annular filter material as. It will be seen therefore that air pressure is at all times free to flow through the central opening of the annular valve closure member 50, and this flow of air is controlled by means of a poppet member 62 which is generally located forwardly of the partition 4-4, but which has a projection which extends through the control port as for abutment with the valve closure members 5%. The poppet member 62 is normally biased rearwardly by a valve return spring 64- with sufiicient force to lift the valve closure member 58 out of engagement with the vacuum valve seat 48. When no actuating force is applied to the control rod D, therefore, the control valve structure B will be in the position shown in the drawing-wherein vacuum is free to flow through the passageway 4e and around the vacuum valve seat 45 to the control port 46, and hence to the rear power chamber 32. From rear power chamber 32, air flows around the end of the partition member B into the annular space 66 between the partition member B and the sidewalls of the shell A to an opening 68 which communicates with the rear power chamber Force from the movable wall structure C is transmitted to a conventional master cylinder, not shown, through a force transmitting member Fone end of which is received in a large diameter bore 70 in the forward end of the cast hub 14. A block of rubber 72 is positioned in the bore 76 between the force transmitting member F and the inner surface of the bore; and in order to transmit reaction force to the control valve structure E, the forward end of the poppet member 62 is positioned in a small diameter opening 74 communicating with the block of rubber '72. Compression of the rubber causes it to flow against the poppet member 62 and exert a reactive force thereon.

As previously indicated the servomotor shown in the drawings is caused to be power actuated by forcing the push rod D forwardly into the servornotor unit. From the at rest position shown in the drawing, poppet member 53 moves forward into engagement with the vacuum valve seat 48, following which the atmospheric valve seat 76 is moved out of engagement with the valve closure member 5t to communicate atmospheric pressure to the rear power chambers 28 and 32 respectively. Differential pressure is thereby created across the diaphragms 22 and 24causing the hub and tubular boss 16 to be moved forwardly thereby transmitting force to the rubber block 72. to cause the force transmitting member F to energize the master cylinder, not shown, which is attached thereto. When forward movement of the control rod D is stopped, air flow continues to the power chambers 23 and 32 for a slight interval thereafter, tocause the hub. structure 14 to move forwardly by an amount sufficiently to allow the valve closure member 56 to again abut the vacuum valve seat is-thereby preventing further pressure differential to be created across the diaphragms 22 and 24. .When it is desired to reduce the braking eflort produced by the servomotor, the control rod D is retracted or'moved rearwardly causing the poppet member 62 to lift the valve closure member 50 out of engagement with the vacuum valve seat 48, and thereby communicate vacuum to both of the rear power chambers 23 and 32 respectively. The differential pressure across the diaphragm-is 24 and 22 is thereby reduced so that the hydraulic pressure in the master cylinder causes the force transmitting member F to move the movable wall structure Crearwardly. When it is. desired to stop further reduction in braking effort, the rearward movement of thepush rod D is stopped, following which the movable wall structure C moves rearwardly a slight amount to again bring the vacuum valve seat 48 into engagement-with the valve closure member 50, and thereby prevent further reduction in the force being developed by the servomotor. A complete removal of force ,on the control rod D .permits the valve return spring or to holdthe valve closure member out of engagement with the vacuum valve seat 48 and thereby permit full vacuum to be developed in both of the rear power chambers 28 and 32 and thereby causing the movable wall structure C to assume theposition shown in the drawing.

According to principles of the present invention, the servomotor structure shown in the drawing is made so that it can be assembled quickly, and so that the housing sections and 12 can be locked together by a novel interlocking structure which is formed as part of the sheet metal parts themselves. The rear shell section 12 is stamped from a piece of sheetmetal into a generally cup shaped structure, and is thereafter slotted circumferentially at equally spaced points a slight distance .rearwardly from its open end. The strips 32 between the slots 80 and the open end of thecup structure 12 are thereafter bowed radially inwardly to provide a locking structure .best seen in FIGURES 2 and 3 of thedrawing. Inthe embodiment shown in the drawings, sixteenstrips 82am providedin the sidewalls of the shell 12, and are equally spaced around its circumference a slightdistance inwardly from its opened end. The front coversection 10 of the servomotor housingis also stamped from a piece of sheet metal, and is provided with a radially turned flanged section 84 the periphery of which is provided with a predetermined clearance with respect to theinternal sidewalls of the shell 12. The fiange-84 of the section 10* is scalloped out as at 86 at sixteen equally spaced points around its periphery to an arcuate shape which will accommodate the bowed sections .82, so that the cover section it} can be inserted into the openend of the section 12 with the bowed sections 82 passing through the scalloped sections 86 of the cover section 10.

As best seen in FIGURE 1, the internal partition member -B has an axially extending peripheral flange 92 that fits into theshell section 12 in a manner permitting the rear diaphragm 22 to be folded over its most rearward end with the bead 88 of the diaphragm being received in the groove 99 in the outer periphery of the flange 92. The

shell section 12 is bent radially inwardly to provide a shoulder 94 against which the edge of the diaphragm 22 can be positioned, and the shoulder 94 is so positioned as to permit the bead of the diaphragm 24 to be clamped between the forward end of the flange 92 and the flange S4 of the cover section 10 when it is locked behind the bowed sections 82.

It is intended that the movable wall structure C and partition member B will be assembled before placing into the shell section 12; and that the outer cover section 10 will be forced into the opened end of the section 12 to compress the bead 3% into sealing engagement between the inner sidewalls of the shell section 12 and the flange 84 before the edges of the flange 84 are rotated in behind the bowed sections 82. In order that the flange 84 will be prevented from being rotated clockwise beyond the point where its full diameter sections or tabs 98 are centered behind the bowed sections 82, a tab 101} is bent axially forwardly from one of the sections 98 so that it abuts the inner surface of one of the bowed sections 82 and prevents further rotation of the cover member It The tab 100, in the preferred embodiment shown in the drawing, projects approximately .060 of an inch out of the end face of the flange 84. .It is further contemplated that the cover member 16 can also be locked against rotation in a counterclockwise direction by means of a similar .tab 102 which faces in the opposite circumferential direction. The tab 1G2 will preferably only be bent a slight amount outwardly of the face of the flange 34 (approximately .020 of an inch) so that it can yield or be bent rearwardly behind one of the bowed sections 82 as the cover plate 10 is rotated clockwise into its locking position shown in the drawing.

It will be apparent that the objects heretofore enumerated have been accomplished, and that there has been provided an inexpensive stamped con-figuration for two' shell sections of a fluid pressure motor and the like which will lock the sections together when they are rotated a slight amount, and which structure is more inexpensive to produce than any method used heretofore.

While the invention hasbeen described in considerable detail, I do not wish to be limited totheparticular constructions shown and described; and it is my intention to cover hereby all novel adaptations, modifications and arrangements thereof which come within thepractice of those skilled in the art to which the invention relates.

We claim:

1. In a fluid pressure servomotor and the like: a stamped open ended sheet metal shell forming an axially extending internal chamber of predetermined uniform cross section adjacent its open end, abutment means around the internal periphery of said shell and spaced a predetermined distance from said open end of said shell, said shell being slit at generally equally spaced intervals around the periphery of said uniform section of said shell a predetermined distance axially outwardly of said abut- V ment means to provide bendable portions of said shellbetween said slits and its open end, said portions being bent radially inwardly, an end cover plate having'a cylindrically shaped peripheral edge and ha-ving a sliding fit with respect to the inside predetermined cross section of said shell, the periphery of said cover plate being notched radially inwardly at intervals matching said bent portions of said shell to be capable of receiving said bent portions, and a movable wall in said chamber and having a diaphragm portion the outer edge of which is operatively clamped between said abutment means and said radially inwardly bent portions of said shell extending radially inwardly over the axially outer face of said cylindrically shaped peripheral edge of said cover plate intermediate said notches to lock said cover plate to said shell.

2. In a fluid pressure servomotor and the like: a stamped open ended sheet metal shell forming an axially extending internal chamber of predetermined uniform cross section adjacent its open end, abutment means around the internal periphery of said shell and spaced a predetermined distance from said open end of said shell, said shell being slit at generally equally spaced intervals around the periphery of said uniform section of shell a predetermined distance axially outwardly of said abutment means to provide bendable portions of said shell between said slits and its open end, said portions being bent radially inwardly to identical radii, an end cover plate having a cylindrically shaped peripheral edge and having a sliding fit with respect to the inside predetermined cross section of said shell, the periphery of said cover plate being notched radially inwardly at intervals matching said bent portions of said shell to be capable of receiving said bent portions, and a movable wall in said chamber and having a diaphragm portion the outer edge of which is clamped between said abutment means and said cover plate, said radially inwardly bent portions of said shell extending radially inwardly over the axially outer face of said cylindrically shaped peripheral edge of said cover plate intermediate said notches to lock said cover plate to said shell.

3. In a fluid pressure servomotor and the like: a stamped open ended sheet metal shell forming an axially extending internal chamber of predetermined uniform cross section adjacent its open end, abutment means around the internal periphery of said shell and spaced a predetermined distance from said open end of said shell, said shell being slit at generally equally spaced intervals around the periphery of said uniform section of shell a predetermined distance axially outwardly of said abutment means to provide bendable portions of said shell between said slits and its open end, said portions being bent radially inwardly, an end cover plate having a cylindrically shaped peripheral edge and having a sliding fit with respect to the inside predetermined cross section of said shell, the periphery of said cover plate being notched radially inwardly at intervals matching said bent portions of said shell to be capable of receiving said bent portions, a movable wall in said chamber and having a diaphragm portion the outer edge of which is clamped between said abutment means and said cover plate, said radially inwardly bent portions of said shell extending radially inwardly over the axially outer face of said cylindrically shaped peripheral edge of said cover plate intermediate said notches to lock said cover plate to said shell, and the peripheral edge portion of said cover plate having a tab bent axially outwardly to abut one of said bent portions of said shell.

4. In a fluid pressure servomotor and the like: a

stamped open ended sheet metal shell forming an axially extending internal chamber of predetermined uniform cross section adjacent its open end, abutment means around the internal periphery of said shell and spaced a predetermined distance from said open end of said shell,

said shell being slit at generally equally spaced intervals around the periphery of said uniform section of shell a predetermined distance axially outwardly of said abutment means to provide bendable portions of said shell between said slits and its open end, said portions being bent radially inwardly, an end cover plate having a cylindrically shaped peripheral edge and having a sliding fit with respect to the inside predetermined cross section of said shell, the periphery of said cover plate being notched radially inwardly at intervals matching said bent portions of said shell to be capable of receiving said bent portions, a movable wall in said chamber and having a diaphragm portion the outer edge of which is clamped between said abutment means and said radially inwardly bent portions of said shell extending radially inwardly over the axially outer face of said cylindrically shaped peripheral edge of said cover plate intermediate said notches to lock said cover plate to said shell, and the peripheral edge portion of said cover plate having a pair of tabs bent axially outwardly and extending in opposite circumferential directions to abut bent portions of said shell and lock said cover plate against rotation.

5. In a sheet metal housing member and the like: a stamped open ended sheet metal shell forming an axially extending internal chamber of predetermined uniform cross section adjacent its open end, abutment means around the internal periphery of said uniform section of shell and spaced a predetermined distance from said open end of said shell, said shell being slit at generally equally spaced intervals around the periphery of said shell a predetermined distance outwardly of said abutment means to provide bendable portions of said shell between said slits and its open end, said portions being bent radially inwardly, an end cover plate having a sliding fit with respect to the inside predetermined cross section of said shell, the periphery of said cover plate being notched radially inwardly at intervals matching said bent portions of said shell to be capable of receiving said bent portions, and resilient means operatively clamped between said abutment means and said cover plate to hold said cover plate against said bent portions, said radially inwardly bent portions of said shell extending inwardly over the axially outer face of said periphery of said cover plate intermediate said notches to lock said cover plate to said shell.

References Cited in the file of this patent UNITED STATES PATENTS 2,525,695 Lombard Oct. 10, 1950 2,574,574 Ives Nov. 13, 1951 2,969,046 Kellogg et al. J an. 24, 1961 FOREIGN PATENTS 711,635 Great Britain July 7, 1954 

1. IN A FLUID PRESSURE SERVOMOTOR AND THE LIKE: A STAMPED OPEN ENDED SHEET METAL SHELL FORMING AN AXIALLY EXTENDING INTERNAL CHAMBER OF PREDETERMINED UNIFORM CROSS SECTION ADJACENT ITS OPEN END, ABUTMENT MEANS AROUND THE INTERNAL PERIPHERY OF SAID SHELL AND SPACED A PREDETERMINED DISTANCE FROM SAID OPEN END OF SAID SHELL, SAID SHELL BEING SLIT AT GENERALLY EQUALLY SPACED INTERVALS AROUND THE PERIPHERY OF SAID UNIFORM SECTION OF SAID SHELL A PREDETERMINED DISTANCE AXIALLY OUTWARDLY OF SAID ABUTMENT MEANS TO PROVIDE BENDABLE PORTIONS OF SAID SHELL BETWEEN SAID SLITS AND ITS OPEN END, SAID PORTIONS BEING BENT RADIALLY INWARDLY, AN END COVER PLATE HAVING A CYLINDRICALLY SHAPED PERIPHERAL EDGE AND HAVING A SLIDING FIT WITH RESPECT TO THE INSIDE PREDETERMINED CROSS SECTION OF SAID SHELL, THE PERIPHERY OF SAID COVER PLATE BEING NOTCHED RADIALLY INWARDLY AT INTERVALS MATCHING SAID BENT PORTIONS OF SAID SHELL TO BE CAPABLE OF RECEIVING SAID BENT PORTIONS, AND A MOVABLE WALL IN SAID CHAMBER AND HAVING A DIAPHRAGM PORTION THE OUTER EDGE OF WHICH IS OPERATIVELY CLAMPED BETWEEN SAID ABUTMENT MEANS AND SAID RADIALLY INWARDLY BENT PORTIONS OF SAID SHELL EXTENDING RADIALLY INWARDLY OVER THE AXIALLY OUTER FACE OF SAID CYLINDRICALLY SHAPED PERIPHERAL EDGE OF SAID COVER PLATE INTERMEDIATE SAID NOTCHES TO LOCK SAID COVER PLATE TO SAID SHELL. 